Hydra are a distant relative of Dragons. Hydras were creatures in Club Penguin, who appear in Medieval Parties, and they come in some Ye Knight's Quests. There was 1 robotic hydra in Club Penguin during the Medieval Party 2011 with 3 heads (A Red, Blue and Yellow). Each Hydra head has its own powers and weakness what penguins must find; and use it to destroy them.

Trivia

Hydras are creatures from Greek Mythology.

From the word Hydra, "Hydro" became a Greek root for Water, as the Hydra lives in the water.